cm_Set and cm_SetIfEmpty

[white]

I suggest to implement a new internal command cm_Set which works similar to the set command in cmd.exe.
I also suggest to implement a new internal command cm_SetIfEmpty which only sets a variable if it doesn't exist yet.

Syntax:

Code: Select all

cm_Set var=value         ; set environment variable
cm_Set [var_part]        ; show list of environment variables, all vars (no parameter) or all vars starting with var_part
cm_SetIfEmpty var=value  ; set environment variable only if it doesn't exist yet

[Fla$her]

What's the point? Give an example of using variables that you create within the current session (not at the start with autorun).

[white]

The point, of course, is to give control over TC's environment space.

Use cases can be many things, it's primarily limited by one's lack of imagination. Some examples:

Set options for a program that uses a environment variable and then run that program
Command: cm_Set myprogram_options=-r -o 64,c:\myprogram\myprogram.exe

Make sure a used environment variable exists, otherwise the variable name and percent signs will be used unchanged
Command: cm_SetIfEmpty my_var=empty,c:\myprogram\myprogram.exe %my_var%

Store a file name to be used later (in this TC session) by several programs of your choice
Command: cm_Set myvar=
Parameter: %P%N

Set the path for a certain program
Command: cm_SetIfEmpty path_start=%path%,cm_Set path=%path_start%;c:\myprogram\bin,c:\myprogram\myprogram.exe

[funkymonk]

Following the many threads and discussions in the forum, there seems to be an increasing demand for scripting or scripting-like functionality in TC:

* commands with (more) parameters
* command lists (also with commands that support parameters, e.g., for defining shortcuts)
* conditional creation of env variables (as in this thread)
* ...

It is great to see that many requests are considered in new TC versions. Thank you indeed, Mr. Ghisler. This is awesome.

But: I increasingly get the feeling that many improvements related to the items above often just "retrofit" features in very specific places in TC (which do not work everywhere in TC, or only with additional effort).

Examples:
* Some commands support parameters, but not when defining shortcuts. --> detour via user commands
* Conditional definition of env variables --> since if-then-else is not supported, cm_Set and cm_SetIfEmpty would be required
* Comma-separated command lists are supported in many places, but sometimes there can be spaces (em_commands) or must not be spaces (autostart commands in view mode definitions) around the commas --> inconsistency
* ...

Wouldn't it be better to think about a real scripting functionality in TC (with a consistent syntax)?
Of course the effort would be quite big, but probably this would provide more consistency and simplify many tasks...

I really fear, that too many situation-specific or context-specific improvements will clutter TC in the long run.


(Maybe this discussion deserves a separate thread -- or should not be raised at all. I will let the forum admins decide.)

[Fla$her]

2white
In the first and third examples, you will create only a variable, and I asked to give examples of their use.

Make sure a used environment variable exists, otherwise the variable name and percent signs will be used unchanged
Command: cm_SetIfEmpty my_var=empty,c:\myprogram\myprogram.exe %my_var%

Why is 'empty' here? There should be nothing at all logically.
And why do you need something with percentages as a parameter to the program? Didn't you know that in Command field, an empty environment variable is expanded to an empty value? There won't be an entry like %my_var%.
I'm asking you to give a real example from practice, not something elusive.

Set the path for a certain program
Command: cm_SetIfEmpty path_start=%path%,cm_Set path=%path_start%;c:\myprogram\bin,c:\myprogram\myprogram.exe

And why do you want to do this during the session, and not at the time of TC launch?

Maybe this discussion deserves a separate thread

There are such topics. You can search.

[mmm]

funkymonk,
I find your concern totally legitimate.
Glad you decided to be vocal about it.

mmm

[white]

In the first and third examples, you will create only a variable, and I asked to give examples of their use.

Their use is explained in the title above it.

Didn't you know that in Command field, an empty environment variable is expanded to an empty value? There won't be an entry like %my_var%.

Are you sure? Try this button and see what ini name is used:

Code: Select all

TOTALCMD#BAR#DATA
"%commander_exe%" /i="%temp%\tc_%myini%.ini"

%commander_exe%
Test non-existing environment vrariable


-1

Set the path for a certain program
Command: cm_SetIfEmpty path_start=%path%,cm_Set path=%path_start%;c:\myprogram\bin,c:\myprogram\myprogram.exe

And why do you want to do this during the session, and not at the time of TC launch?

Why should I want to change the path at the time of TC launch for a program I might not use?

[Fla$her]

Their use is explained in the title above it.

There are no specific live examples that would be useful outside of scripts.

Are you sure? Try this button and see what ini name is used:

Yes, I'm sure, because I actively use it. Topics: 1, 2.

29.07.18 Fixed: Distinguish between empty environment variables and non-existing environment variables. Replace %variable% with empty string in the first case (32/64)

Why should I want to change the path at the time of TC launch for a program I might not use?

In PATH are written paths to directories with programs, not the full names of programs. Does it make sense to add a directory there just to run the program only within one session? To me, such use seems unproductive. I don't remember any situations when I needed something like that.

Glad you decided to be vocal about it.

See one of the author's answers.

[white]

Their use is explained in the title above it.

There are no specific live examples that would be useful outside of scripts.

Scripts, other TC buttons, programs that use certain environment variables, program that support environment variables in their configuration.

Are you sure? Try this button and see what ini name is used:

Yes, I'm sure, because I actively use it. Topics: 1, 2.

29.07.18 Fixed: Distinguish between empty environment variables and non-existing environment variables. Replace %variable% with empty string in the first case (32/64)

I see what you mean. With "empty" I meant a non-existing environment variable, not a variable that holds an empty string.

Why should I want to change the path at the time of TC launch for a program I might not use?

In PATH are written paths to directories with programs, not the full names of programs. Does it make sense to add a directory there just to run the program only within one session? To me, such use seems unproductive. I don't remember any situations when I needed something like that.

Some programs are weird and require their bin folder to be in the path or they can't find their libraries.

[Fla$her]

Scripts, other TC buttons, programs that use certain environment variables, program that support environment variables in their configuration.

In my memory, there were a couple of requests that concerned remembering the full file name. This is copying it to the folder of the active panel or returning to it by cd. I don't remember anything else useful. So I'm asking you to give live examples, not abstract ones.

In any case, you can make hotkeys (autorun: SetHotkeyAction + SetEnv + GetCurrentItem) to create environment variables during the session without TC commands.

I see what you mean. With "empty" I meant a non-existing environment variable, not a variable that holds an empty string.

Anyway I don't understand the logic of cm_SetIfEmpty my_var=empty,. If there is no variable, then must be done so that it does not exist? Meaninglessness.
And in this case, the name should be changed from cm_SetIfEmpty to cm_SetIfNotExist, cm_SetIfAbsent or cm_SetIfMissing.

Some programs are weird and require their bin folder to be in the path or they can't find their libraries.

To run, you always need the folder where the program is located. It doesn't matter if it's bin or something else.
But I'm beginning to understand what you need. You often conduct tests with some program and want to run it regardless of the change of the working directory (tree navigating, tab switching, etc.). Am I thinking in the right direction?

[jinsight]

2funkymonk,

I, too, find your concern totally legitimate and am glad you decided to be vocal about it.

I, too, would prefer a scripting or scripting-like functionality in TC rather than a shoe-horned "retrofit"
response that creates many situation-specific or context-specific improvements that will clutter TC in the long run.

[Fla$her]

2jinsight
I suggest you also follow my link from the bottom of the post.

[white]

I see what you mean. With "empty" I meant a non-existing environment variable, not a variable that holds an empty string.

Anyway I don't understand the logic of cm_SetIfEmpty my_var=empty,. If there is no variable, then must be done so that it does not exist? Meaninglessness.

That example would assign the string "empty" to the variable my_var. It could be any value the user wants. Sorry for the confusion by using this example.

And in this case, the name should be changed from cm_SetIfEmpty to cm_SetIfNotExist, cm_SetIfAbsent or cm_SetIfMissing.

Or cm_SetIfUndefined, or whatever Ghisler would prefer.

Some programs are weird and require their bin folder to be in the path or they can't find their libraries.

To run, you always need the folder where the program is located. It doesn't matter if it's bin or something else.

It isn't about the folder where the program is located in order to run the program. In that case you would simply enter full path of the program. It's about programs that use the path variable to locate their library files.

But I'm beginning to understand what you need. You often conduct tests with some program and want to run it regardless of the change of the working directory (tree navigating, tab switching, etc.). Am I thinking in the right direction?

No.

[Fla$her]

2white
I haven't seen any live examples from you.

Sorry for the confusion by using this example.

Thanks at least for clarifying.

In that case you would simply enter full path of the program.

Won't you get tired of repeatedly writing the full path in each session?

It's about programs that use the path variable to locate their library files.

Well, these are interrelated things.

[white]

I haven't seen any live examples from you.

I'm not sure what you mean by "live examples".

Won't you get tired of repeatedly writing the full path in each session?

The commands I gave were meant to be used for example in a button. Not to be typed each session.